In the cotton processing industry, raw cotton material is processed to remove foreign materials such as dust, stalks, stems, and other materials from the cotton fibers. As part of the processing, cotton fibers and associated foreign matter are transported through ductwork from one part of a processing facility to a finishing area of the processing facility. An efficient method and an apparatus are needed to remove most of the associated foreign matter from the cotton fibers during its pneumatic transport through ductwork, before the cotton fibers arrive at the finishing area of the processing facility.
Prior methods of removal of foreign matter include passing an air stream entrained with cotton fibers and foreign matter over or through a grid of bars, or directing such an air stream into a screen, rotating cylinder, or other obstacle, with the cotton fibers changing direction along with the air flow due to the lower density of the cotton fibers, and the foreign matter impacting the obstacle and being removed from the air stream due to the higher density of the foreign matter. A third prior method consists of directing cotton fiber and foreign matter between spiked rollers and a plate or grid of bars, with the spikes on the rollers contacting the cotton fibers, and forcing the cotton fibers to an exit while the higher density foreign matter is directed to a separate exit. All of the prior methods impose a force on the cotton fibers, with damage to the cotton fibers and some loss of cotton fibers from processing as the fibers are forced against a wall, grid of bars, or spikes.
The invented apparatus and method of operation provides for separation of cotton fibers from foreign matter without application of a destructive force and without damaging of cotton fibers. The invented apparatus and method of operation utilize an apparatus that does not require additional energy input to the flowing air stream within the facility's cotton fiber transport ductwork, therefore providing a cost-efficient apparatus and method to remove foreign matter from cotton fibers.